In January of 1990, I had my twenty one month old Standard Poodle puppy
euthanised. She was one of three puppies in a litter of eleven to die of
Juvenile Renal Disease (JRD). All three of the puppies with the disease
appeared healthy, and grew normally until clinical signs appeared at ten
months in one, and twenty months in the other two. She died two weeks after
being diagnosed. The disease is devastating. The prognosis is dismal.
Nobody expects to lose a puppy of that age.

Despite the fact that several articles on Juvenile Renal Disease and
Familial Renal Disease were published in veterinary journals in the 1970s,
and many others have been published since that time, on JRD in Dobermans
Pinschers, Alaskan Malamutes, Norwegian Elkhounds, Samoyeds, Standard
Poodles, and Golden Retrievers, most individual cases of JRD are treated by
owners and veterinarians as isolated occurrences rather than as the
manifestation of a genetic disease. The type of renal disease, also called
Renal Dysplasia, from which my puppy died, is also seen in Airedale
Terriers, Alaskan Malamutes, Bedlington Terriers, Boxers, Bulldogs, Chow
Chows, Great Danes, Great Pyrenees, Irish Wolfhounds, Keeshonds, King
Charles Spaniels, Miniature Schnauzers, Old English Sheepdogs, Swedish
Foxhounds, Shiz Tzus, Lhasa Apsos, Soft Coated Wheaten Terriers,
Portuguese Water Dogs, and Yorkshire Terriers. It is just recently being
seen in Golden Retrievers, a breed in which it had not before been
recognized as a familial disease. Other types of genetic renal disease are
also well known in Rottweilers, Shar Peis, Miniature Poodles, Cairn
Terriers, Welsh Corgis,Pekingese, Shetland Sheep Dogs, Collies, Beagles,
Basenjis, Bull Terriers and Cocker Spaniels, among others. Similar forms
of genetic renal diseases may have different modes of inheritance in
different breeds. Other forms of familial and congenital renal diseases
seen in the breeds listed above include Glomerulopathy, Amyloidosis,
Polycystic kidneys, and Fanconi-like syndrome.

Early symptoms of Juvenile Renal Disease include drinking copious amounts
of water, something that might not be readily apparent in a house with more
than one dog, frequent urination, and dilute urine which has little color
or odor. Some affected puppies leak urine, many do not. Often a puppy
owner's earliest complaint is about the difficulty of housebreaking a puppy
later discovered to have JRD. The volume of water consumed, and, in some
puppies,leakage of urine can make housebreaking a formidable task. As the
disease progresses, vomiting, weight loss, anorexia, lethargy, and muscle
weakness are seen. There is sometimes a chemical odor to the breath as a
result of metabolic waste not being excreted by the kidneys.

In breeds in which juvenile renal diseases are seen, symptoms may be noted
as early as a few weeks after birth; and affected puppies are almost
without exception symptomatic before two years of age. Some puppies fail
to thrive: most grow normally until symptoms appear. Puppies with renal
dysplasia may appear clinically normal for extended periods of time before
developing signs of chronic renal failure. The rate at which renal
dysplasia progresses to overt renal failure depends on the severity of the
initial renal lesions. Dogs commonly do not exhibit clinical signs of renal
failure until less than 25% of renal function remains. A dog with renal
dysplasia affecting only one kidney may be symptom free, and the dog may
live a normal lifetime.

If a dog under two years of age is found to have an elevated BUN (blood
urea nitrogen) and creatinine, and significant protein in the urine, as
indicated by an increased urine protein:creatinine ratio, JRD should be
strongly suspected. Abdominal palpation by a veterinarian may reveal small
irregularly shaped kidneys. An ultrasound can be a useful diagnostic tool,
since the kidneys are often atrophied and underdeveloped. It must be kept
in mind, however, that kidneys from affected dogs may be normal size.

The most accurate method for diagnosing JRD is a wedge biopsy from one
kidney taken any time after the second month of life, or a histopathologic
exam after death. A biopsy or autopsy of a puppy less than two months of
age would not be fruitful, since the normally immature kidneys cannot be
distinguished from those affected by JRD. The slides should be examined by
an experienced pathologist. There are a number of pathologists who have a
considerable interest in this disease. It is not reasonable to expect
most puppy owners who are not breeders, to agree to a wedge biopsy, since a
more accurate diagnosis will not affect the treatment or prognosis, and
since the necessary anesthesia is not without risk.

If the reduction in renal function is identified early, when only increased
water consumption and urination are evident, medical management can be
instituted immediately. Although the renal damage is not reversible, the
quality and length of the puppy's life may be improved by early treatment.

Treatments for the symptoms of JRD include a low protein and low phosphorus
prescription diet, such as Hill's K/D. The predominant effect of the low
protein diet is to minimize production of uremic toxins so that the patient
feels better. Low protein diets may help extend life in dogs. Phosphorus
is more important in this regard, since high phosphorus accelerates renal
failure, and restricted phosphorus slows it down. K/D is low in
phosphorus, so it remains a good food for dogs in this condition. In
addition to diet, IV fluids can be administered to correct disturbances
created by the retention of uremic toxins. Epogen can be prescribed to
treat the anemia of chronic renal failure, resulting in improving the
quality, and probably the length of life. Kidney dialysis for dogs is
offered at several veterinary medical sites. The University of California,
Davis, Veterinary Medical School is performing kidney transplants, but
transplanted kidneys in dogs are commonly rejected, and involve an
extraordinary expense and commitment. UC Davis will only do a renal
transplant if the red cell cross matching and blood type is a perfect
match. and if the tissue typing is also a perfect match. One of four
healthy littermates of an affected puppy may offer such a match.

George Lees, DVM of Texas A & M University is currently doing research on
Juvenile Renal Disease in Cocker Spaniels. Both VetGen, in Michigan, and
the Canine Genome Project at the University of California, Berkeley, are
searching for the gene marker(s) for the Juvenile Renal Disease seen in
Soft Coated Wheaten Terriers.

Although progress is being made, waiting for DNA testing to become readily
available is not a feasible solution to the problems of many genetic
diseases. Selectively breeding away from carriers now is the only
responsible action. In some instances, careful breeders have succeeded in
largely eradicating some genetic disorders from their breeds. Success
depends on a number of factors. Every puppy buyer must be encouraged to
report any major illness back to the breeder. Breeders must have a clear
understanding of the modes of transmission of genetic disorders that affect
their breeds. Known carriers as well as possible carriers, (littermates and
offspring of those discovered to be carriers) must be conscientiously kept
out of the gene pool, or used very judiciously. A method of communication
among breeders must be established.

Clearly, an open registry such as the open registry begun in July, l992 for
Sebaceous Adenitis (SA) in Standard Poodles (this disease also occurs in
other breeds) is an important step forward and an invaluable resource. Open
registries as well as research databases in many canine diseases are being
established at the Genetic Disease Control For Animals (GDC) in Davis,
California. In Europe, open registries have made it possible for careful
breeders to greatly reduce the number of cases of some genetic disorders.

An open registry would include the names of carriers of the disease as well
as the names of dogs who are clear, those who when bred to a carrier did
not produce any cases of the disease in a litter of significant size.
Obviously, the early onset of Juvenile Renal Disease allows carriers to be
identified much sooner than does a disease which manifests itself later in
life.

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